67 research outputs found

    Molecular basis of biocide resistance and susceptibility in bacteria

    Get PDF
    The molecular basis of biocide resistance and susceptibility in Serratia and mycobacteria was investigated using transposon mutagenesis approach. The killing and growth inhibitory effects of four biocides (triclosan, cetylpyridinium chloride, chlorhexidine diacetate and alkaline orf/io-phthalaldehyde) on Serratia marcescens Dbll, Mycobacterium smegmatis mc2155, M. chelonae type strain NCTC 946, M. abscessus type strain ATCC 19977, and Escherichia coli NCTC 1048 were studied using minimal inhibitory concentration determination, biocide killing, and potassium leakage tests. Transposon mutagenesis using a mariner system did not produce any M. smegmatis mc2155 mutants with altered biocide sensitivity. In contrast mutagenesis of S. marcescens Dbll using the mini-Tn5Km2 transposon system led to the isolation of 26 biocide mutants. Increased resistance, susceptibility and mixed biocide phenotypes were observed in the mutants. Alteration in antibiotic susceptibility was also noted. The locations of transposon insertion in all but two of the mutants were determined, and 14 putative genes coding for putative proteins with diverse functions were found to be disrupted. These functions included anabolism and catabolism, gene regulation, cell envelope biosynthesis, porin, energy production, and virulence. Two mutants, one deficient in the outer membrane protein A (OmpA), and another deficient in the nucleoid-associated protein (NdpA), were complemented. Complementation of the ndpA mutant which showed increased resistance to cetylpyridinium chloride and chlorhexidine diacetate, but was sensitive to triclosan, lead to restoration of the wild type phenotype. Complementation of the ompA mutant, which showed multiple sensitivity to chlorhexidine diacetate, triclosan, and or/Zio-phthalaldehyde however, did not restore the wild type phenotype. The cloned ompA gene was shown to be transcribed but not translated in the complemented mutant. In summary, the genetic basis for biocide resistance in S. marcescens Dbll is multi-factorial and encoded by several novel loci worthy of further study

    Management of hospitalized drug sensitive pulmonary tuberculosis patients during the Hajj mass gathering: A cross sectional study

    Get PDF
    Background To document the management of drug-sensitive TB patients during the Hajj and assess compliance with the Saudi TB management guidelines. Method The study was conducted in hospitals in Makkah during the 2016 and 2017 Hajj seasons. Structured questionnaire was used to collect data on relevant indices on TB management and a scoring system was developed to assess compliance with guidelines. Results Data was collected from 31 TB cases, 65.4% (17/26) were Saudi residents. Sputum culture was the only diagnostic test applied in 67.7% (21/31) of patients. Most (96.8%, 30/31) confirmed TB cases were isolated, but only 12.9% (4/28) were tested for HIV and merely 37% (10/27) received the recommended four 1st-line anti-TB drugs. Guideline compliance scores were highest for infection prevention and control and surveillance (9.6/10) and identifying TB suspects (7.2/10). The least scores were obtained for treating TB (5.0/10) and diagnosing TB (3.0/10). Conclusions Healthcare providers training and supervision are paramount to improve their knowledge and skill and ensure their compliance with existing TB management guidelines. However, there may be a need for the introduction of an international policy/guideline for TB control and management during mass gatherings such as the Hajj to guide providers’ choices and facilitate monitoring

    Meningococcal disease surveillance in the Asia-Pacific region (2020): The global meningococcal initiative.

    Get PDF
    The degree of surveillance data and control strategies for invasive meningococcal disease (IMD) varies across the Asia-Pacific region. IMD cases are often reported throughout the region, but the disease is not notifiable in some countries, including Myanmar, Bangladesh and Malaysia. Although there remains a paucity of data from many countries, specific nations have introduced additional surveillance measures. The incidence of IMD is low and similar across the represented countries (<0.2 cases per 100,000 persons per year), with the predominant serogroups of Neisseria meningitidis being B, W and Y, although serogroups A and X are present in some areas. Resistance to ciprofloxacin is also of concern, with the close monitoring of antibiotic-resistant clonal complexes (e.g., cc4821) being a priority. Meningococcal vaccination is only included in a few National Immunization Programs, but is recommended for high-risk groups, including travellers (such as pilgrims) and people with complement deficiencies or human immunodeficiency virus (HIV). Both polysaccharide and conjugate vaccines form part of recommendations. However, cost and misconceptions remain limiting factors in vaccine uptake, despite conjugate vaccines preventing the acquisition of carriage.S

    The global meningitis genome partnership.

    Get PDF
    Genomic surveillance of bacterial meningitis pathogens is essential for effective disease control globally, enabling identification of emerging and expanding strains and consequent public health interventions. While there has been a rise in the use of whole genome sequencing, this has been driven predominately by a subset of countries with adequate capacity and resources. Global capacity to participate in surveillance needs to be expanded, particularly in low and middle-income countries with high disease burdens. In light of this, the WHO-led collaboration, Defeating Meningitis by 2030 Global Roadmap, has called for the establishment of a Global Meningitis Genome Partnership that links resources for: N. meningitidis (Nm), S. pneumoniae (Sp), H. influenzae (Hi) and S. agalactiae (Sa) to improve worldwide co-ordination of strain identification and tracking. Existing platforms containing relevant genomes include: PubMLST: Nm (31,622), Sp (15,132), Hi (1935), Sa (9026); The Wellcome Sanger Institute: Nm (13,711), Sp (> 24,000), Sa (6200), Hi (1738); and BMGAP: Nm (8785), Hi (2030). A steering group is being established to coordinate the initiative and encourage high-quality data curation. Next steps include: developing guidelines on open-access sharing of genomic data; defining a core set of metadata; and facilitating development of user-friendly interfaces that represent publicly available data
    corecore